The present invention relates to a time base corrector, used with an image reproducing system such as a video disc player, in which a video signal is sampled to be digitized and the jitter of the video signal is removed.
A time base corrector (TBC) for removing the change in time base (jitter) of a video signal, used with a video disc and a VTR, is heretofore realized by sampling the video signal with a clock following the jitter of the video signal to write the resultant signal to a memory. At this time, the clock is generated using an analog VCO (voltage controlled oscillator) which is controlled by a PLL (phase locked loop). As an example for performing the full digital processing with PLL including VCO, as described in JP-A-2-58947, there is known a method in which a clock of low frequency is generated with a digital VCO, and the clock thus generated is multiplied by a frequency of a fixed oscillator to perform the frequency conversion to obtain a clock having a predetermined frequency. In this case, however, jitter is generated in the clock due an unnecessary frequency component which was produced during the processing, and the video signal is processed with that clock, and therefore, the jitter is also generated in the video signal. As a result, in the case where the video signal includes a carrier chrominance signal, there arises a problem in that a beat is generated in a chrominance signal.